 /*******************************************************************************
  * Copyright (c) 2006 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  * IBM Corporation - initial API and implementation
  ******************************************************************************/

 package org.eclipse.ui;

 import org.eclipse.ui.part.EditorPart;

 /**
  * Represents a source of Saveable objects (units of saveability). Workbench
  * parts that show more than one unit of saveability, or whose units of
  * saveability change over time, should implement this interface in order to
  * provide better integration with workbench facilities like the Save command,
  * prompts to save on part close or shutdown, etc.
  * <p>
  * IMPORTANT: As of 3.2, implementers of <code>ISaveablesSource</code> must
  * satisfy the following conditions:
  * <ul>
  * <li>If ISaveablesSource is implemented by an IWorkbenchPart:
  * <ul>
  * <li>the part must implement <code>ISaveablePart</code></li>
  * <li>if any of its Saveable objects are dirty, the part must return
  * <code>true</code> from {@link ISaveablePart#isDirty()}</li>
  * <li>the part must return <code>true</code> from
  * {@link ISaveablePart#isSaveOnCloseNeeded()} if it is dirty (the default
  * behaviour implemented by {@link EditorPart})</li>
  * <li>the part must not implement {@link ISaveablePart2}</li>
  * </ul>
  * </li>
  * <li>If ISaveablesSource is implemented by a non-part (possible as of 3.2.1 and 3.3):
  * <ul>
  * <li>the Workbench's {@link ISaveablesLifecycleListener} (obtained from the
  * Workbench by calling
  * <code>workbench.getService(ISaveablesLifecycleListener.class)</code>) must
  * be notified of any change to the result of {@link #getSaveables()} </li>
  * <li>getActiveSaveables() should be implemented to return an empty array
  * </li>
  * </ul>
  * </ul>
  * If any of these conditions are not met, it is undefined whether the Workbench
  * will prompt to save dirty Saveables when closing parts or the Workbench.
  * </p>
  * <p>
  * These conditions may be relaxed in future releases.
  * </p>
  *
  * @since 3.2
  */
 public interface ISaveablesSource {

     /**
      * Returns the saveables presented by the workbench part. If the return
      * value of this method changes during the lifetime of
      * this part (i.e. after initialization and control creation but before disposal)
      * the part must notify an implicit listener using
      * {@link ISaveablesLifecycleListener#handleLifecycleEvent(SaveablesLifecycleEvent)}.
      * <p>
      * Additions of saveables to the list of saveables of this part are
      * announced using an event of type
      * {@link SaveablesLifecycleEvent#POST_OPEN}. Removals are announced in a
      * two-stage process, first using an event of type
      * {@link SaveablesLifecycleEvent#PRE_CLOSE} followed by an event of type
      * {@link SaveablesLifecycleEvent#POST_CLOSE}. Since firing the
      * <code>PRE_CLOSE</code> event may trigger prompts to save dirty
      * saveables, the cancellation status of the event must be checked by the
      * part after the notification. When removing only non-dirty saveables,
      * <code>POST_CLOSE</code> notification is sufficient.
      * </p>
      * <p>
      * The listener is obtained from the part site by calling
      * <code>partSite.getService(ISaveablesLifecycleListener.class)</code>.
      * </p>
      * <p>
      * The part must not notify from its initialization methods (e.g. <code>init</code>
      * or <code>createPartControl</code>), or from its dispose method. Parts that
      * implement {@link IReusableEditor} must notify when their input is changed
      * through {@link IReusableEditor#setInput(IEditorInput)}.
      * </p>
      *
      * @return the saveables presented by the workbench part
      *
      * @see ISaveablesLifecycleListener
      */
     Saveable[] getSaveables();

     /**
      * Returns the saveables currently active in the workbench part.
      * <p>
      * Certain workbench actions, such as Save, target only the active saveables
      * in the active part. For example, the active saveables could be determined
      * based on the current selection in the part.
      * </p>
      *
      * @return the saveables currently active in the workbench part
      */
     Saveable[] getActiveSaveables();
 }

